公开(公告)号：US20160329073A1

公开(公告)日：2016-11-10

申请号：US15107764

申请日：2014-12-26

Applicant: HOYA CORPORATION

Inventor： Takashi MAEDA ,  Takumi KUHARA

IPC: G11B5/73 ,  G11B5/82

CPC classification number: G11B5/73 ,  G11B5/7315 ,  G11B5/82

Abstract: When waviness having a wavelength component of 10 to 500 μm in the circumferential direction of a main surface of a disk-shaped substrate is acquired and slopes are acquired from the waviness at an interval of 50 to 100 μm, the substrate being used in a magnetic disk on which recording or reading is performed using a DFH head, an average value of absolute values of the slopes is 0.45×10−4 or less. This magnetic-disk substrate is used in a magnetic disk and a magnetic-disk drive device.

Abstract translation: 在圆盘状基板的主面的圆周方向上取波长成分为10〜500μm的波纹，以波纹为50〜100μm的范围获得斜率，将该基板用于磁性 使用DFH头进行记录或读取的盘，斜率的绝对值的平均值为0.45×10 -4以下。 该磁盘基板用于磁盘和磁盘驱动装置。

公开(公告)号：US20170256278A1

公开(公告)日：2017-09-07

申请号：US15603964

申请日：2017-05-24

Applicant: HOYA CORPORATION

Inventor： Takashi MAEDA ,  Takumi KUHARA

IPC: G11B5/73 ,  G11B5/82

CPC classification number: G11B5/73 ,  G11B5/7315 ,  G11B5/82

Abstract: When waviness having a wavelength component of 10 to 500 μm in the circumferential direction of a main surface of a disk-shaped substrate is acquired and slopes are acquired from the waviness at an interval of 50 to 100 μm, the substrate being used in a magnetic disk on which recording or reading is performed using a DFH head, an average value of absolute values of the slopes is 0.45×10−4 or less. This magnetic-disk substrate is used in a magnetic disk and a magnetic-disk drive device.